<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>轮子</title>
  <style>
    *{
      margin: 0;
      padding:0;
      box-sizing: border-box;
    }
    :root{
      --button-height:32px;
      --font-size:14px;
      --button-bg:white;
      --button-active-bg:#eee;
      --border-radius:4px;
      --color:#333;
      --border-color:#999;
      --border-color-hover:#666
    }
  </style>
</head>
<body>
  <div id="app">
    <ch-button>我爱JS</ch-button>
  </div>
  <script src="./src/app.js"></script>
</body>
</html>